Apparatus for surfacing metals



Sept. 10, 1940. H. R. HERCHENRIDER APPARATUS FOR SURFACING METALS Filed on. 50, 19:57

3 Sheets-Sheet l INVENTOR Henry R, He/chenr/ber INV; NTO R 168mg 6. He/ahem Ha 5 flffprnej 5 Sheets-Sheet 2 H. R.. HERCHENRI'DER- APPARATUS FOR SURFACiNG METALS Filed Oct. 50, 1937 Sept; '10, 1940.

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Sept. 10, 1940- H. R. HERCHENRIDER 2,214,373

APPARATUS FOR SURFACING METALS Filed Oct. 30, 1937 a Sheets-Shet s INVENTOR Patented Sept. 10, 1940 PATENT OFFICE APPARATUS FOR SURFACHQ'G METALS Henry R. Herchenrider, Pittsburgh, Pa., assignor to Minnesota Mining & Manufacturing Company, St. Paul, Minn., a corporation of Delaware Application October 30, 1937, Serial No. 171,960

4 Claims.

My invention relates more particularly to the art of grinding and polishing 'sheets of thin metal, but certain features thereof may also be employed in connection with grinding and polishing of other articles. a

In the grinding and polishing of metal sheets for the purpose of giving them a smooth or polished finish, or for the purpose of removing rough spots or discolorations such as oxide stains, difliculty is encountered because of. the heat generated by grinding which causes expansion of the thin metal at the grinding. zone, so that the sheet tends to bulge. Upon cooling of the sheet, there will not be sufilcient shrinkage or contraction to restore the sheet to a plane or flat condition.

In some instances attempts have been made to overcome this difiiculty of warping or bulging of the sheet, by first grinding the sheet at the rear side to cause the sheet to bulge slightly at the zone to be ground and then grinding the front side of the sheet, at the bulged or protruding areas. I

In those cases where an abrasive belt is employed, the belt will become excessively heated through frictional contact with the sheet, with the result that it will deteriorate rapidly, particularly under the higher grinding pressures. Another objection to some of the methods heretofore employed arises out of the. fact that in the case of very thin metal sheets, stray particles of grit on the table which supports the sheet while it is being ground will deform or dent the sheet slightly, so that dimp1ing and uneven polishing result.

One object of my invention is to provide a means for maintaining sheets at a cool temperature while being ground, through absorption or dissipation of the heat ordinarily developed by grinding, to thereby prevent distortion of the metal; to permit of higher grinding pressures, and to permit longer use of the grinding element.

Another object of my invention is to provide an improved form of support for sheets While being ground, in order to eliminate the dimpling or denting above referred to.

Still another object of my invention is to provide an improved manner-of guiding and holding anabrasive belt in contact with the work.

Another object of my invention is to provide a supporting table of such form that imperfections or spots of very small area can be removed more accurately, and whereby cooling fluid such as water'or cold air can be brought more effectively into engagement with the under side of the sheet, opposite to the area being ground.

As shown in the accompanying drawings, Figure 1 is a side elevation of one form of machine;

Fig. 2 is an end View thereof; Fig. 3 is a view on an enlarged scale taken on the line III-III of Fig.1; Fig. 4 is a viewtaken on the line IV--IV of Fig. 3 Fig. 5 is a longitudinal sectional view of a modified form of grinding and polishing machine; ;Fig. 6 is a view taken on the line VIVI of Fig. 5, and Fig. 7 shows a modification of a portion of the structure of Fig. 5.

Referring first to Figs. 1 to 4, I show pedestals 9 which support track rails ID, the track rails being connected by a beam II, the members 9,

l0 and II constituting an unitary rigid frame- -work for the other parts of the apparatus.

A carriage or tableframe is provided which comprises a rectangular framework consisting of side bars l2, a front bar 13 and a rear bar l4, all rigidlyconnected together. Brackets I5 are secured to the front and rear bars and are provided at their lower ends with rollers or wheels l6 which ride upon the track rails I0. A spotting head i8 is mounted upon the beam II, a sheet l9 being supported upon the carriage for movement over the head Ill. The sheet l9 which is to be polished is detachably secured to the table by means of clamping fingers 2|] and 2i which are pivotally connected to one another at 22,

the finger 20 constituting an extension of the body portion 23 of the clamp. The clamp member 23, is of angular form to partially embrace a slide bar 24 which is slidably mounted upon the front angle bar. l3 of the table frame. A

gripping finger or lever 25 is pivotally connected to the clamp body 23 and engages the underside of the slide bar 24. A clamp screw 26 has threaded engagement with the rear end of the finger 2i and abuts against the outer end of the clamp lever 25. When the screw 26 is turned downwardly, it will cause the clamp 'lever.25 to grip the bar 24, and will'alsd rock the finger 2| in a clockwise direction to grip the sheet l9. It will be understood that when the screw 26 is loosened, the'sheet will be released from the gripping fingers 20 and 21, and can thereby be removed and the clamps 23 can be shifted lon-' gitudinally of the slide bar 24 in order to accommo'dat'e sheets of various lengths. Y h

In .order to shift a sheet to various positions longitudinally of the table, for grinding various areas thereof, I provide shifting apparatus comprising. a bracket 2! connected to one end of the slide bar 24. A sprocket ch-ain28 has its ends secured to the bracket 21 and passes around a sprocket wheel 29 that is journalled in end bar l2. The chain also passes around sprocket wheel 30 that is journalled in the front bar l3 of the table frame at a point adjacent to the spotting head I8. The sprocket 30 is provided with a hand wheel 3| which when turned will shift the slide bar 24 and thereby permit movement of justable on the bracket 39. in order to maintain proper tension on the belt 33. A bar 4| of tubular or other suitable form is supported at its ends by the brackets 36 and 39. -A backing-up roller 42 is journalled in a yoke 43 having extension 44 which is pivotally connected to a link 45, that is in turn pivotally connected to a yoke 46 which loosely embraces a rail 41 which at its ends is supported. from the tubular bar 4| by means of clamps 48'. Anti-friction guides 49 are provided on the yoke 46 so that the roller 42 can be shifted longitudinally of the rail 41. A hand lever 50 is pivotally connected to the yoke 43 and to the lower side of the yoke 46, and when lowered and raised will move'the roll 42 into and out of pressing engagement with the belt 33.

The roll 42 may bear directly against the belt 33, but in those cases where the belt 33 has to be driven at very high speeds such as at perhaps from 2,000 feet to 7*,000 feet per minute, there would be too much vibration and wear of the roll. -At these high speeds, the shaft and bearings of the roller would have a very short life, because it is desirable in most casespto use rollers of small diameters in grinding small areas on sheets, and the bearings for the roller would necessarily have to be very small. The rolls frequently will be no more than two inches or four inches in diameter.

In order to prevent wear and strain during grinding operations, I .interpose between the belt 33 and the roller a friction strip 5| which may be of canvas or other suitable material, and which is connected at its ends to brackets 52 that may contain spools whereby the strip can be shifted longitudinally to bring difierent portions thereof into frictional engagement with the belt 33, as it becomes worn. The friction strip 5| is normally stationary and is,"therefore, rubbed by the abrasive belt 33. To reduce wear, the contacting surfaces of the strip and the belt may be lubricated by graphite or the like. The brackets 52 are of such height that the strip 5| will be out of contact with the belt 33 except at about its mid portion when it is pressed downwardly by the roller 42, at which time the belt 33 will, of course, be brought into engagement with the sheet being ground. The belt 33 will be coated with suitable abrasive or polishing material such as aluminum oxide, silicon carbide, emery, garnet, rouge etc.

The spotting head I8 is provided with a perforated top plate or surface 54 beneath which are water'chambers 55 and 56 divided'by a partition 51. The top 54 is crowned slightly from its ends and its sides toward its central point, so that the very small imperfect areas can be ground or polished without unnecessary abrasion of the valves 60 and 6|.

adjacent portions of the sheet, since the sheet will flex downwardly on the plate 54. Water or other cooling fluid is directed into the cham-. bers55 and 56 through pipes 58 and 59 respectively, such pipes being individually controlled by When the abrasive belt is in contact with the metal sheet, above the head 54, water will be directed into either or both of the chambers55 and 56, depending upon the' position of the edge of the sheet with respect" to the spotting head. If the sheet is being ground close to one edge, the orifices above one of the chambers may be uncovered, in which case water or other cooling fluid will be directed into only the other chamber. The sheet will thereby be kept cool at the grinding area. The sheets to be ground will ordinarily be from perhaps one-fourth inch in thickness down to the lightest gauges. An overflow trough 62 extends circumferentially of the spotting head and conducts waste water to a conduit 63. A suitable number of rollers 65 are journalled in the table frame members I3 and I4 for supporting long sheets.

It will be seen from the above that the sheets can be shifted both longitudinally and laterally with respect to the spotting head l8, and that any portions thereof can be brought into grinding position above the spotting'head, whereupon the roller 42 can be lowered to push the abrading belt against the sheet l9, and during grind ing operations can be shifted on the guide rail 41 with respect to the head 3. During a grindbecoming heated.

Referring now to Figs. and 6, I show a structure which may conveniently be employed for surfacing entire sheets instead of only certain areas thereof. In this structure, a frame work supports rollers I0 and 1|, which may serve as guide rollers for a sheet 14 or may serve as pinch rolls to drive a sheet. Sheet-supporting rollers 12 are also journalled in the framework. A billy roll 13 is journalled in the framework either for idling movement through travel of the sheet, or capable of being driven. The roller 13 comprises a metal tubular portion and a rubber sheath 16 which are provided with fluid discharge orifices. A curved valve plate f'I'I is mounted within the tube I5. The tube 15 is rotatably supported upon the valve tube 11. The upper portion of the valve tube 11 is cut away, as shown more clearly in Fig. 5. At its ends it is closed by plugs 18 that are supported for yieldable veragainst the under side of the sheet. The valve.

tube 11 confines the discharge of the fluid to the area beneath the point of grinding.

An abrasive belt 8| extends around pulleys or I drums 62 and 83 journalled in the upper portion of the framework the drum being driven by a motor 85. A presser roll 85 is also journ'alled in the framework and serves to hold the belt 6| against the sheet 14.

The rubber facing 16 on'the billy roll serves to prevent grit particles at the under side of the sheet fromdenting or pressing up the sheet, since such particles will recede into or be pressed into the face of the roll. The water will also serve to wash theroll and the under side of the sheet clear of any such grit particles.

In Fig. 7 I have shown still another manner directed inwardly toward the grinding zone so asof cooling theunderside of a sheet being ground. In this case, the abrasive belt 81 is held in. contact with a-sheet 88 by a presser roll 88. The billy roll 90 maybe covered as in Fig. 6, but instead of having cooling fluid directed through the roll, I provide separate spray pipes SI for cooling the under side of the sheet. The spray is to get the cooling fluid as nearly as possible beneath the area being ground.

While in the forms 01' apparatus above described an abrasive belt is employed, it will be understood that the water cooling will be equally effective if a rotary grinding element such as a disc or roll is brought into direct contact with the sheet instead of utilizing an abrasive belt 1 and a presser roll therefor.

I claim as my invention:

1. The combination with a device for grinding" one surface of a metal=sheet and a perforated supporting irnember for engaging the opposite surface of the sheet, of means for directing a flow of cooling fluid through the said perfumtions and against the sheet.

like comprising an abrading element movable into engagement with one surface of the sheet and a supporting member positioned to engage the opposite side of the sheet and of convex form in longitudinal and transverse directions, the said supporting, member being perforated toadmit cooling fluid therethrough to the adjacent side of the sheet.

3. Grinding apparatus for sheet metal or the like, comprising an abrading element movable into engagement with the sheet and a hilly roll Ior supporting the opposite side of the sheet, the said roll being faced with yieldable material, and provided with orifices through which fluid may be directed against the sheet.

4. Grinding apparatus for sheet metal or the like, comprising an abrading element movable into engagement with the sheet, and a billy roll for supporting the opposite side of the sheet, the

roll having an internal passageway for the flow of cooling fluid and being provided with radiallyextending orifices for discharging said fluid against the sheet.

HENRY R'. HEROHENRIDER. 

